A plasma display panel (hereinafter, called a PDP) has a front plate and a rear plate. The front plate includes a glass substrate, display electrodes formed on a main surface of the glass substrate, a dielectric layer covering the display electrodes to function as a capacitor, and a protective layer made of magnesium oxide (MgO) and formed on the dielectric layer.
In order to increase the number of primary electrons released from the protective layer, there has been disclosed a technique of adding impurities to an MgO protective layer (for example, refer to Patent Literature 1). Further, there has been disclosed a technique of forming MgO particles on a base film made of an MgO thin film (for example, refer to Patent Literature 2).